Roger Stone, who had already resigned as council leader, Gwendoline Ann Russell, Jahangir Akhtar and Shaukat Ali were suspended pending investigation after Ed Miliband said last week that large numbers of young people in Rotherham were systematically abused and let down by those who should have protected them.

Akhtar stepped down from his role as deputy leader of Rotherham council and vice-chair of the police and crime panel when it was reported that he knew about a relationship between an underage girl and man who had abused her. In November he said he had always maintained his "absolute innocence of the scurrilous allegations".

Police said after an inquiry they found no evidence to substantiate the allegations, reported in the Times. In a statement in November the force said: "Following an investigation into allegations made against councillor Jahangir Akhtar published in the Times on 23 August, South Yorkshire police have now completed the inquiry and found no evidence to substantiate the claims."

In addition, two former members of the party, Shaun Wright and Maurice Kirk, will require national executive committee approval if they want to rejoin Labour.

"We've acted as we can to have the accountability and transparency we need in Rotherham," Tristam Hunt, the shadow education secretary, told Sky News. "We know there was a culture of denial … and we are acting to have a clean sweep."

Wright, South Yorkshire's police and crime commissioner, has refused to stand down despite intense pressure. He was the council cabinet member with responsibility for children's services in the town between 2005 and 2010.

In announcing an investigation of the police's handling of the abuse of at least 1,400 children in Rotherham between between 1997 to 2013, Ch Con David Crompton said: "A fully independent and impartial investigation is required to ensure that people have confidence that organisations or any individuals will be investigated fairly, rigorously and with complete impartiality."

The investigation will examine the role of both the police and council and address any wrongdoings or failings, which will allow "appropriate action to be taken".

He added: "We must give victims the confidence to come forward in the knowledge that all agencies will listen, will act, provide appropriate support, and relentlessly pursue those who offend against our young people." Crompton has begun discussions to identify an appropriate force to carry out the inquiry.

Asst Ch Con Ingrid Lee added: "We treat CSE [child sexual exploitation] with the utmost sensitivity and I urge anyone who has concerns about a child who could be at risk to come forward. Our officers will relentlessly pursue all evidence and do everything they can to achieve justice for victims and bring those responsible to justice.

"We cannot do this alone – we need the continued support of our communities and I urge anyone who is aware of a young person being sexually exploited to contact police so that we can protect those at risk."

The latest moves follow a BBC Panorama documentary screened on Monday night in which a Home Office official who investigated the sexual exploitation of children in Rotherham accused the council of being involved in the unauthorised removal of information from her office.

Her report in 2002 suggested there were then more than 270 victims of the scandal, which was finally exposed last week. She told Panorama she had sent her report to both the council and the Home Office on a Friday, but when she returned on Monday she found her office had been raided.

"They'd gained access to the office and taken my data, so out of the number of filing cabinets there was one drawer emptied and it was emptied of my data. It had to be an employee of the council," she said.

The researcher, who was not named by Panorama, also said she had been accused of being insensitive when she told one official that most of the perpetrators were from Rotherham's Pakistani community. A female colleague talked to her about the incident. "She said you must never refer to that again – you must never refer to Asian men," she said.

The said that at one point the council tried to get her sacked and the report was never published. A draft of the report severely criticised agencies working to tackle the child exploitation in the area, including "alleged indifference towards, and ignorance of, child sexual exploitation on the part of senior managers".